/Engine/Source/Editor/UnrealEd/Public/PackageTools.h
Utility function that gathers all async compilable objects from given packages and flush them to make sure there is no remaining async work trying to load data from said packages.
static void FlushAsyncCompilation ( [TArrayView](API\Runtime\Core\Containers\TArrayView)< [UPackage](API\Runtime\CoreUObject\UObject\UPackage) *const > Packages )